The French flag was flown as the building was lit up in red, white and blue Friday evening.

“On behalf of the residents of San Francisco, I express my deepest sorrow for the heartbreaking tragedy unfolding in Paris today,” Mayor Ed Lee said in a written statement. “We stand in solidarity with our friends in our sister city of Paris, Mayor Hidalgo and with people all across France as they struggle with the aftermath of this very dark day. The victims of these senseless acts of violence will remain in our prayers.”

The mayor said while there is no known threat to San Francisco, the police department is on heightened alert with extra patrols.

Other landmarks across the world were lit up in the colors of France, including One World Trade Center in New York, Wembley Stadium in London and the CN Tower in Toronto.